This invention relates to new compositions and to the preparation of foamed polyester resins. In particular, it relates to storage stable dispersions and their use in the curing and foaming of unsaturated polyester resins.
It is known in the art that aromatic diacyl peroxides can be used as polymerization initiators in the curing of unsaturated polyester resins (See, e.g. U.S. Pat. Nos. 4,016,112, 4,056,611 and 4,347,331).
It is also known in the art that unsaturated polyester resins can be foamed by the generation of CO.sub.2 obtained from the decomposition of carbonates and bicarbonates (See, U.S. Pat. Nos. 3,479,303; 4,016,112; 4,028,289; 4,119,583; 4,122,047; 4,347,331 and British Pat. No. 2,029,834).
Prior attempts to combine the CO.sub.2 generating material and the polymerization initiator into a readily useful, stable composition have not been successful.
It is therefore an object of the present invention to devise a system whereby the chemicals necessary for the curing of and foaming of an unsaturated polyester resin can be present in a readily useable, stable composition.
Other objects of this invention will become readily apparent from the ensuing description.